Insomnia, or sleeplessness, is a sleep disorder in which there is an inability to fall asleep or to stay asleep as long as desired. Insomnia is most often thought of as both a medical sign and a symptom that can accompany several sleeps, medical, and psychiatric disorders characterized by a persistent difficulty falling asleep and/or staying asleep or sleep of poor quality. Insomnia is typically followed by functional impairment while awake. Insomnia can occur at any age, but it is particularly common in the elderly. Insomnia can be short term (up to three weeks) or long term (above 3–4 weeks); it can lead to memory problems, depression, irritability and an increased risk of heart disease and automobile related accidents.
Insomnia can be grouped into primary and secondary, or morbid, insomnia. Primary insomnia is a sleep disorder not attributable to a medical, psychiatric, or environmental cause. It is described as a complaint of prolonged sleep onset latency, disturbance of sleep maintenance, or the experience of non-refreshing sleep. A complete diagnosis will differentiate between free-standing primary insomnia, insomnia as secondary to another condition, and primary insomnia co-morbid with one or more conditions.
Types of insomnia
Insomnia can be classified as transient, acute, or chronic.
1. Transient insomnia lasts for less than a week. It can be caused by another disorder, by changes in the sleep environment, by the timing of sleep, severe depression, or by stress. Its consequences – sleepiness and impaired psychomotor performance – are similar to those of sleep deprivation.
2. Acute insomnia is the inability to consistently sleep well for a period of less than a month. Insomnia is present when there is difficulty initiating or maintaining sleep or when the sleep that is obtained is non-refreshing or of poor quality. These problems occur despite adequate opportunity and circumstances for sleep and they must result in problems with daytime function. Acute insomnia is also known as short term insomnia or stress related insomnia.
3. Chronic insomnia lasts for longer than a month. It can be caused by another disorder, or it can be a primary disorder. People with high levels of stress hormones or shifts in the levels of cytokines are more likely than others to have chronic insomnia. Its effects can vary according to its causes. They might include muscular fatigue, hallucinations, and/or mental fatigue. Chronic insomnia can cause double vision.
Patterns of insomnia
Symptoms of insomnia:
- difficulty falling asleep, including difficulty finding a comfortable sleeping position
- waking during the night and being unable to return to sleep
- feeling un refreshed upon waking
- daytime sleepiness,irritability or anxiety
Sleep-onset insomnia is difficulty falling asleep at the beginning of the night, often a symptom of anxiety disorders. Delayed sleep phase disorder can be misdiagnosed as insomnia, as sleep onset is delayed to much later than normal while awakening spills over into daylight hours.
It is common for patients who have difficulty falling asleep to also have nocturnal awakenings with difficulty returning to sleep. Two thirds of these patients wake up in middle of the night, with more than half having trouble falling back to sleep after a middle of the night awakening.
Early morning awakening is an awakening occurring earlier (more than 30 minutes) than desired with an inability to go back to sleep, and before total sleep time reaches 6.5 hours. Early morning awakening is often a characteristic of depression.
Poor sleep quality
Poor sleep quality can occur as a result of, for example, restless legs, sleep apnea or major depression. Poor sleep quality is caused by the individual not reaching stage 3 or delta sleep which has restorative properties.
Major depression leads to alterations in the function of the hypothalamic-pituitary-adrenal axis, causing excessive release of cortisol which can lead to poor sleep quality.
Symptoms of insomnia can be caused by or be associated with:
- Use ofpsychoactive drugs (such as stimulants), including certain medications,herbs, caffeine, nicotine, cocaine, amphetamines, methylphenidate, aripiprazole,MDMA, modafinil, or excessive alcohol intake.
- Withdrawal from anti-anxiety drugs such asbenzodiazepines or pain-relievers such as opioids
- Previousthoracic surgery.
- Heart disease.
- Deviated nasal septum and nocturnal breathing disorders.
- Restless legs syndrome, which can cause sleep onset insomnia due to the discomforting sensations felt and the need to move the legs or other body parts to relieve these sensations.
- Periodic limb movement disorder(PLMD), which occurs during sleep and can cause arousals of which the sleeper is unaware.
- Painan injury or condition that causes pain can preclude an individual from finding a comfortable position in which to fall asleep, and can in addition cause awakening.
- Hormoneshifts such as those that precede menstruation and those during menopause.
- Life events such asfear, stress, anxiety, emotional or mental tension, work problems, financial stress, birth of a child and bereavement.
- Gastrointestinal issues such as heartburn or constipation.
- Mental disorderssuch as bipolar disorder, clinical depression, generalized anxiety disorder, post traumatic stress disorder, schizophrenia, obsessive compulsive disorder, dementia, and ADHD
- Disturbances of thecircadian rhythm, such as shift work and jet lag, can cause an inability to sleep at some times of the day and excessive sleepiness at other times of the day. Chronic circadian rhythm disorders are characterized by similar symptoms.
- Certainneurological disorders, brain lesions, or a history of traumatic brain injury.
- Medical conditionssuch as hyperthyroidism and rheumatoid arthritis.
- Abuse of over-the counter or prescription sleep aids (sedativeor depressant drugs) can produce rebound insomnia.
- Poorsleep hygiene, e.g., noise or over-consumption of caffeine.
- A rare genetic condition can cause aprion-based, permanent and eventually fatal form of insomnia called fatal familial insomnia.
- Physical exercise. Exercise-induced insomnia is common in athletes in the form of prolonged sleep onset latency